1. Field of the Invention
The present invention relates to an error correction coding method and apparatus, and more particularly, to a threefold error correction coding method and apparatus for reinforcing an error correction capability of a system which uses an inner error correction code and an outer error correction code with respect to data compressed at a high compression rate.
2. Description of the Related Art
A high definition digital video cassette recorder (HD-DVCR) is a system using an inner error correction code and an outer error correction code for channel coding. The HD-DVCR can record or reproduce signals adopting the A-TV (Advanced Television) system of the United States. The HD-DVCR is a system used for data storage in which data compressed according to the MPEG II standard can be stored, and from which the stored data is reproduced. The HD-DVCR uses the same recording format and channel processing portion as those of the SD-DVC (standard digital video camcorder). For example, for a 525/60 system, the HD-DVCR uses 10 segment recording formats in which one-frame of data is recorded on 10 tracks, and uses an inner error correction code and an outer error correction code for error-correcting the compressed data.
However, since the HD-DVCR uses variable length coding according to the MPEG II standard, it provides a higher compression rate than the SD-DVC which provides a compression rate of 1/5 or so. Therefore, when the HD-DVCR and the SD-DVC use the same error correction techniques, the HD-DVCR provides a lower picture quality than the SD-DVC, in accordance with an error degree in the transmission channel. That is, even though the SD-DVC provides an excellent picture quality, the HD-DVCR causes severe degradation in the picture quality and makes picture restoration impossible.